The statement relative to the use of teflon tape is NOT correct in all parts of
Teflon tape is not prohibited by the Uniform Building Code used as a model
across the US. Some states & municipalities may prohibit its use, however that
is a local decission usually based on a political decission or union pressure.
There is no safety or engineering reason not to use teflon tape on the gases
we’re talking about here.
There is, however, one requirement, you CANNOT use the WHITE teflon tape. For
use with gas piping you MUST use the YELLOW teflon tape to be in compliance with
the Building Code.